Method of forming plywood



Aug. 4, 1942. T, R. ROBINSON.

METHOD of FORMING PLYWOOD Original Filed May 29, 1939 3 Sheets-Sheet 1J.. im?

om 1 2. .MM.. ww WW n i n mm km. 0 n L w I Q E Q m S E. m H:::ill--13mmS @w 3 .2 r1- fi S mw INVENTOR 7' hogms 1?. Robinson ATTORNEY Aug. 4,1942. T. R. ROBINSON A METHOD OF FORMING PLYWOOD' Original Filed May 29,1959 3 Sheets-Sheet 5 INVENTOR a T A Patented Aug. 4, 1942 Divided andthis application March 8,

I 1940, Serial No. 322,945

2 Claims.

This invention relates to a method of formin plywood and a generalobject of the invention is to provide a method of laying up or formingplywood by which waste of material is reduced to a production in theplant is speeded up, cost of manufacture is reduced, and a better andmore uniform product is provided.

This application is a division of my copending application Serial No.276,369, filed May 29, 1939.

In the manufacture of plywood it has heretofore been common practice tolay up each panel of plywood separately by taking strips of crossbanding stock (sometimes referred to as core stock) as they come fromthe glue rolls, placing the required number of layers of this crossband- -ing stock between suitable face members to build up the number ofplies desired and then curing the glue in the panels. As the crossbandin stock is usually of random widths, in laying up, of

separate plywood panels it is generally necessary to allow the crossbanding to overhang the edges of the panels a substantial amount. Thisoverhanging cross banding has glue onboth faces thereof and the overhangis later trimmed away as waste. It is thus seen that this commonlyemployed method of laying up plywood results in a waste of cross bandingstock and a waste of the glue on the trimmed away cross banding.

In accordance with this invention, 1. provide a method of laying upplywood in such a manner that the face members thereof are in line andin slightly spaced apart edge to edge relation and the cross bandingstock is in a layer extending continuously over both the face membersand the spaces between the face members at the time of laying up. Thenthe cross banding .is severed at the spaces between the face membersafter the laying up is completed. This provides a method by which theplywood is laid up in continuous in line operation and the loss of crossbanding stock and glue due to overhang of cross banding is reduced to aAnother object of this invention is to provide, laid up panels ofplywood which can be handled before curing of the glue without danger ofdisplacing the plies thereof. Another object is to pass fastener meansthrough portions of the panels, which will be removed in the latertrimming operation, to temporarily secure the several plies of a paneltogether prior to the curing of the glue in the panels.

Another object is to provide an eflicient method of coordinating thelaying up of plywood, composed of difierent numbers of plies, in such amanner as to most efliciently utilize thelabor,

the veneer presses, and the other machinery used.

Another object is to provide novel and efllcient means for cutting thecross banding between adjacent laid up plywood panels and for staplingor otherwise fastening together the piles of the in my invention,throughout which drawings like reference numerals indicate like parts:

Figure 1 is a somewhat diagrammatic side elevation, with parts insection and parts broken away, showing apparatus of preferred form forcarrying out this invention;

Fig. 2 is a plan view of apparatus shown in Fig. l, with parts brokenaway; I

Fig. 3 is a fragmentary side elevation, on a larger scale than Figs-1and 2 and looking in the direction indicated by broken line 3-3 of Fig.2, of cut off and stapling means used in carrying out the invention;

Fig. 4 is a fragmentary view partly in plan and partly in sectionsubstantially on broken line l4 of Fig. 3; v Fig. 5 is a fragmentaryview partly in elevation and partly in section substantially on brokenline 55 of Fig. 3;

Fig. 6 is a fragmentary plan view showing parts of a link belt controlmeans and devices associated therewith;

Fig. 7 is-a fragmentary detached side elevation showing parts of themechanism connected with the link belt control means;

Fig. 8 is a detached fragmentary view partly in plan and partly insection showing the grooved glue roll around which flexible conveyormeans pass;

Fig. 9 is a fragmentary side elevation of a modified form of cut off andstapling machine mechanism;

Fig. ,10 is a fragmentary view, partly in plan and partly in section andtaken substantially on broken line Ill-Ill of Fig. 9, showing theapparatus in Fig. 9 and showing somewhat diagrammatically certainelectrical and mechanical con--,

'trol devices not shown in Fig. 9;

Fig. 11 isa fragmentary side elevation of a modified form of cut offmeans;

Fig. 12 is a plan view of the devices shown in Fig. 11 with partsthereof'broken away; and

Fig. 13 is a side elevation, with parts broken the conveyor members 32.

away and with parts in section, of a modified form of control means forthe staplingand cut on means.

Referring to Figs. 1 to 8, the numeral 23 designates endless travelingconveyor means supported for movement on suitable sheaves 2|. Some ofthe sheaves 2| are mounted on a driven shaft 13 positioned at an endportion oi conveyorjl. The I upper lap of conveyor means 23 has anupwardly inclined portion 22 toward the head end of the conveyor 20 andwhere the laying up of the plywood isstarted and a substantiallyhorizontal portion 23 toward the other end where the laying up of theplywood is completed.

A pair of glue spreading rolls 24 and 23 are provided near the head endof the conveyor 20. These glue spreading rolls 24 and 23 are preferablypositioned above the head end of the conveyor 23, as shown in Fig. 1,and are adapted to have cross banding stock 28 passed therebetween forthe purpose of spreading glue evenly on both sides of this cross bandingstock 23. The cross banding stock is the stock positioned between twoface, members 21 and 23 of the plywood with its grain extending at rightangles to the grain of the face members 21 and 28.

' The lower glue roll 25 operates with a portion of its periphery in aglue'receptacle 29 and another glue rece tacle 30 is provided inconnection with .the upper glue roll 24. The conventional parts of theglue spreading means not here involved are illustrated somewhatdiagrammatically and not described. The lower glue roll 25 has annulargrooves 3| in the peripheral portion thereof, see Fig. 8, for thereception of flexible endless conveyor members 32. The conveyor members32 pass around the lower glue roll 26 in the grooves 3| and are furthersupported on other rollers 33 to provide glue coated conveyor membersfor transporting the cross banding stock from the glue rolls to alocation where such cross banding stock is to be positioned on lowerface members 21 which are being carried by conveyor 20. When theconveyor members 32 are positioned as shown in Fig. 1, they may deliverthe cross banding stock to which the glue has been applied directly ontothe lower face members 21. Preferably the'conveyor members 32 are offlexible wire, such as twisted wire cable. These cables are glue coatedand move with the cross banding and their contact area on the crossbanding stock is relatively small, thereby insuring uniform distributionof glue on the cross banding stock including the portions contacting Ifthe cross banding stock comprises a plurality of random width pieces,the conveyor members 32 may deliver the cross banding stock directly onlower face members 21. In such case an operator is preferably employedto properly position this cross banding on the lower face members.

Also standard glue rolls, as commonly used, may be employed andpositioned t deliver pieces of glue coated cross banding stock toward anoperator. In such case the cross banding stock will pass longitudinallythrough the glue rolls as distinguished from the transverse travel ofthe cross banding stock through glue rolls 24 and 25. In such event theglue coated cross banding stock will be delivered to an operator whowill position the pieces of glue coated cross banding stock on the lowerface members 21.

If the random width pieces. of cross banding stock have been edge gluedtogether to form a continuous strip, the cross banding stock may bedirectly delivered on the lower face members 21.

The lower face members 21 are placed on the portion 22 of the conveyor23 in line and in slightly spaced apart edge to edge relation, so as toleave a relatively narrow space 34 between each two adjacent facemembers, said space 34 being relatively narrow so that waste is reducedto a minimum. The savings in cross banding stock and glue thereon by theuse of my invention are readily apparent as the amount of cross more.

banding stock between face members may be reduced to a minimum (as abouttwo inches) while in prior art practices the overhang of the crossbanding stock was often twelve inches or The cross banding 26 is laidcontinuously over the face members 21 and across the spaces betweenadjacent face members 21.

After the cross banding 26 is laid on the lower face members 21, upperface members 23 corresponding in size and shape to the lower facemembers are placed on the cross banding 23 in registration, so far aspractically possible, with the lower face members 21. This provides laidup plywood in'which adjacent panels are for the most part connected witheach other by cross banding stock. If the edges of adjoining pieces ofcross banding stock happen to fall at the location of the spaces 34between adjacent face members, it will make no difference in the methodor in the operation of the apparatus or in the resulting product.

After the laying up of the panels is completed, said panels pass afastener applying and cut oil station at which securing means, such asstaples, are passed through the laid up panels adjacent the edges of theface members and the cross banding between adjacent panels is severed.These securing means are for the purpose of securing the plies of thelaid up panels against relative movement while they are being handledand before the glue has been cured. The securing means is trimmed awaywhen the panels are trimmed after curing of the glue.

One form of cut oil and stapling means is shown in Figs. 1 to 7 incl.This means comprises upright frame members 35 supported on horizontalframe bars 36 that are provided at the sides of the conveyor 20 andextend beyond the end of the conveyor 20. Two of the upright framemembers 35 are provided at each side of the machine and the framemembers 35 at each side of the machine cooperate to form upright guideslots 31 wherein a cross bar 38 is guided for vertical movement. Therespective end portions of the cross bar 38 are pivotally connected byoutwardly protruding pins 39 with the upper end portions of uprightconnecting rods 40. The lower end portions of the connecting rods 40 areconnected with circular bands 4| that extend around discs 42. The twodiscs 42 are eccentrically mounted on a commoncross shaft 43 and aresecured in corresponding angular positions on said shaft 43. Obviouslyrotation of the shaft 43 will move the connecting rods 40 longitudinallyand at the same time will impart a swinging motion thereto. Thelongitudinal movement stapling and cutting location, the glue is in an thas its two end portions secured to the respective connecting rods 40,whereby the knife means will be moved vertically and swingingly' withsaid connecting rods. A knife 45 is secured to the bar 44 and providedwith a cutting edge 46 for clipping the cross banding stock. Ahorizontal reinforcing rib 41 is provided on one side of the knifecarrying bar 44 to increase the strength and rigidity of said bar andslots 48 are provided in said rib 41 for purposes hereinafter explained.

A die block 49 extends crosswise of the machine. The two end portions ofthe die block. 49 rest on the horizontal frame bars 36 at the sides ofthe machine and preferably are provided with guide members 50 whichoperate in-grooves in the frame bars 36. Preferably the end portions ofthedie block, which rest on the frame bars 36. are flat on the bottomside and the bottom portion of said die block is of heavier constructionthroughout the remainder of its length to provide rigidity. The upperside of the die block is.substantially fiat and is disposedsubstantially in the plane of the conveyor means 20 so that plywoodcarried on the conveyor means 20 will be passed over this die block.Obviously replaceable inserts of well known form, not hereinshown, maybe provided in this die block, if desired, against which the knife andstapling tools may operate.

The lower portions of the upright frame members 35 are spaced apart farenough to provide working clearance for the ends of the die block. Tworollers 52 are provided in transversely spaced apart relation on eachend portion of the die block 49 and the respective connecting rods 46pass between the rollers 52 and engage therewith in'such a manner thatthe transverse movement of the connecting rods 46 will impart areciprocatory movement to the die block 49. When the die block 49 isbeing moved in one direction it will move with the plywood and willsupport the plywood during the cutting and stapling operation.

A bridge member comprising two transversely spaced apart bars 53, seeFigs. 3, 4 and 5, is positioned in vertically spaced relation above theupper side of the die block 49, see Fig. 5, and is secured to the dieblock 49 by foot portions 54 that are provided at each end of the bridgemember and rest on and are secured to the die block 49. This leaves aspace 54' between the bars 53 of the bridge member and the die block 49through which the plywoodpasses. The bars 53 serve as supports for aplurality of stapling devices 55. As these stapling devices are of awell known standard form of construction readily obtainable on themarket, they are herein shown diagrammatically and not described indetail.

The stapling devices 55 are operated by plunger members 56 that areconnected with the vertically reciprocablecross bar 38. The plungermembers 56 on one side of the knife carrying bar 44 operate through theslots 48. Preferably four stapling devices are provided and thesedevices are positioned so that they will drive 'two staples or fastenersin each end portion of each of two adjacent panels during each cycle ofoperation. This provides for the insertion of mechanical fastening meansin each panel at four locations. Obviously a greater or less number ofthe stapling devices 55 may be used if desired. Also to provide forstapling panels of non-uniform width a plurality of the slots 48 may beprovided in rib 41 through which the plungers 56 at one side of theknife carrying bar 44 may operate. 7

When the laid up plywood panels arrive at the subsequently slip or shiftrelative to each other while they are being handled and before the gluehas been cured.

Preferably the upper end portion of each plunger 56 passes through ahole in a cross member 5'! that is secured by means 56 to thereciprocable cross bar 38. A nut 59 is provided on.

each plunger 56 above the cross member 51. A I

compression spring 60 is provided on each plung- 'er 56 below the crossmember 51 with the upper end thereof in engagement with the cross member51 and the lower end thereof resting on a nut 6| on the plunger. Whenthe bar 38 is ,moved upwardly the plungers 56 will be elevated thereby.When the bar 36 is moved downwardly, a force will be yieldingly exertedon the plungers 56 through the springs 66 to operate the staplingdevices. The springs 60 thus serve to permit further downward movementof the connecting.

rods 40 after the stapling devices have contacted the plywood, thusmaking it possible to staple plywood of different thicknesses withoutadjusting the stapling device operating means and also reducing thedanger of straining or damaging parts of the stapling devices.

Devices are provided for imparting one cycle of operation to thestapling and cutoff means during the time the portions of the crossbanding stock, which extend across the space between the face members ofadjacent plywood panels, are passing under the knife 45. This isaccomplished by connecting the cross shaft 43 with driving means bywhich the power to 'drive the shaft 43 is transmitted through 'a singlerevolution clutch so that the shaft 43 will be advanced one completerevolution at each cycle of operation. As single revolution clutches arewell known pieces of mechanism readily obtainable on the market, and asno particular type thereof is necessary herein, the single revolutionclutch herein is diagrammatically shown and the details thereof are notdescribed. Manually controlled means are illustrated in Figs. 2, 6 and 7for starting the operation of the single revolution clutch.

Referring to Figs. 1 to '7, the cross shaft 43 is connected with asingle revolution clutch 62 to which power is supplied by a continuouslydriven shaft 63. I show the shaft 63 connected by drivi'ng means 18 witha power transmission means I! that is driven by a motor l6. Also I showdriving means l5 connecting the shaft 63 with the shaft I 9 for drivingthe conveyor 20 and show driving means 14 connecting shaft IS with ashaft 1'! for driving discharge conveyor means 16 of a form hereinafterdescribed. Operation of the single revolution clutch 62 is controlled bya lever 64 connected by a link 65 with a lever 66 on a shaft 61. Theshaft 61 is adapted to be oscillated in one direction by a lever 68 thatis connccted by a link 69 with another lever 10. The lever 10 is mountedon a pivot 1| and positioned in substantial alignment with the knife 45and alongside a movable pin type endless link belt 12 which serves as acontroller. The pivot 1| is preferably adjustably mounted to permitcompensation for delay in operation of the single revolution clutch andparts connected therewith.

the thickness of the link belt and are slidable transversely through thelinks of said link belt as best illustrated in Fig. 6. A cam member 14,positioned adjacent the inner side of the link belt .12, engages withany of the movable pins 18 which have been pushed inwardly, and moves vsaid pins outwardly as respects the link belt 12 after the pinshave-operated the lever 18. Preferably a hold down member 14' isprovided to resist any tendency of link belt 12 to move upwardly.

when a pin I8, thereof encounters lever I8. After a plywood panel hasbeen laid up, an operator pushes one of the pins 18 inwardly at alocation in line with the space between the face members of two adjacentplywood panels. The link belt 12 travels at the same speed as theconveyor 28 and the pin 13 thus pushed inwardly will engage with thelever 18 and oscillate the shaft 88 and engage the single revolutionclutch 82 and thereby operate the knife 45 just as the cross banding,which extends across the space 34 between the edges of adjacent facemembers of the pLvwood, is positioned under the knife 45. This willoperate the knife 45 to cut the cross banding between the two adjacentplywood panels and at the same time operate the stapling devices 55 todrive staples through the superposed plies of each of two adjacentpanels. A spring 18 will return the shaft 81 and parts connectedtherewith to the inoperative position as soon as the pin 13 releases thelever 18, and the single revolution clutch 82 will only impart onerevolution to the cross shaft 43 each time it is operated.

As alternatives for the manually controlled link belt 12" forcontrolling the operation of the stapling and cut off means, I haveillustrated types of automatic control, as the photo-electric cell ofFigs. 9 and and the catch means of Fig. 13.

'The knife 45 and the stapling devices 85 move horizontally with the dieblock 49 and all of these parts are moving in the same direction and atapproximately the same speed at the time the cutting and staplingoperations are performed.

From the cut off and stapling devices, the laid up panels pass ontodischarge conveyor means preferably composed of a plurality of belt typeconveyors 18. The end portions of the conveyors 18, adjacent the cut offand stapling devices, preferably are not connected with each other, butthe other end portions of said conveyors l8 preferably are all connectedwith the same driven shaft Tl. When the discharge conveyor members 78are in a horizontal position, they are operable to deliver laid upplywood panels onto any suit able transfer means by which said panelsmay be transported to press means for curing the glue.

The conveyor members 18 are supported by suitable means which permitsthem to be lowered into an inclined position to transfer laid up panelsof plywood to another conveyor by which said panels are returned to thehead of the assembly line for the purpose of having more plies addedthereto. I have shown each conveyor member 18 supported by a link 18that is connected with a lever 18 on a shaft 88. The shaft nects with asubstantially horizontal return conveyor 88. The higher end of theinclined return of the link belt 12, are of greater length thanconveyormeans aft-1s connected with a shaft to that is prefer-ably positionedjust in front of and slightly lowerthan the shaft 11 of the conveyormeans 18. The conveyors 84 and 85 are driven in the direction indicatedby the arrows in Fig. l by any suitable driving means such as drivingmeans I28, Fig. 1, connected to any suitable.

source of power (not shown). Conveyors 84 and 85 are driven at a higherspeed than the conveyors 20 and 18 to quickly remove panels that arebeing transferred from conveyor means." to inclined return conveyormeans 84. The conveyor members I8 are not connected by any cross membersexcept the shaft 11 and said members 18 are transversely offset relativeto the traveling belts of the inclined return conveyor 84. This makes itpossible to lower the conveyor members 18 below the plane of the top ofthe conveyor 84 to transfer panels from the conveyor members 18 to theconveyor 88. Positioning the shaft 88 a short distance inwardly from,and a short distance below, the plane of the shaft 11, and using rollersor sheaves of the samesize on these two shafts keeps the conveyor 84below and clear of the plywood panels when the conveyor members 18 arehorizontal, and leaves the conveyor 84 above the plane of the conveyormembers 18 throughout its entire length when the conveyor members 18 arelowered into the dotted line position shown in Fig. l. The belts ofthese two conveyors travel in opposite directions and the arrangement ofshafts 88 and 11, shown inFig. l,

avoids bringing the panels into contact with conveyor belts which aremoving in directions opposite to the direction of movement of thepanels.

In the operation of the devices shown in Figs.'1 to 8, the conveyorsoperate continuously. An operator positioned near the head portion 22 ofconveyor 28 places lower face members 21 on said conveyor oneafteranother in line and in spaced apart edge to edge relation. As theselower face members travel past the delivery end of the conveyor members32, the glue coated cross banding 28 is either delivered directly ontothe lower face member 21 or is placed by an operator on said face member21. This cross banding extends crosswise of the face members and iscontinuous so that it covers the face members and extends across thespaces between the face members. After the cross banding has beenplaced, another operator places upper face members 28 on top of thecross banding in substantial registration with the lower face members.After the lower face members are properly positioned, the pins 13 of thelink belt 12, which are positioned opposite the spaces between the facemembers; are pushed inwardly. As the pins 13, that are pushed inwardly,successively engage the lever 10 the single revolution clutch 82 iscaused to impart successive cycles of movement to the knife and staplingdevices to sever the cross banding between the panels and drive staplesin the panels. If more plies are to be added to the panels, an operatorto, makes possible the production of plywood pan-- els of three plies orof more than three plies on the same assembly line and with the sameapparatus and same number of operators without any loss in eiiiciency.

aaeneei ply panels or one five ply panel. Thus the pro-' duction of theconveyor line may be kept in synchronism with the needs of the hotpresses.

In Figs. 9 and I have shown alternative cut off, staple device andconveyor drive means which differs from the out off, staple device andconveyor drive means shown in Figs. 1 to '7 to the extent that theconveyors and plywood thereon are stopped and remain immovable duringthe cutting off and stapling operations. In said Figs. 9 and 10substantially all parts of the knife and staple deviceand conveyordevices are similar to those shown in Figs. 1 to 7 except that the knifeis secured to the cross bar 38 instead of to the connecting rods All,bearing slots 31 for knife and bell crank shifter lever 9a which isfulcrumed on pivot ldii.

The apparatus shown in Figs. 9 and 10 operates in substantially thesamemanner as the previously described devices except that the die block,stapling devices and knife do not move transversely and the plywood isstopped and held stationary during each cutting and fasteningopercarryin bar it are made longer by changing the shape of framemembers 35, the rollers 52 on the end portions of the die block 4'9 areomitted, and the die block 69 is fixedly secured to the frame bars 38,by means such as bolts 81. All parts in Figs. 9 and 10 which are similarto those in Figs. 1 to 7 are correspondingly numbered and are not hereinfurther described in detail.

The driving and control means shown in Figs. 9 and 10 difier from thosepreviously described and are as follows: The lever 64 of the singlerevolution clutch B2 is connected by the link 65 with the plunger 88 ofa solenoid 88 which is connected by conductors 89 with a source ofenergy 90. A normally open switch 9!, controlled by a retarded relay 92,is interposed in theconductors 89 to open and close the circuit to thesolenoid 88. A light responsive cell 83, of a form well known andcommonly termed an electric eye, is positioned so that it will besubjected to reflected light from a source of light 93' directed againstone side of the traveling plywood. The cross banding, being coated withglue, will reflect a different amount of light than the face members,This contrast may be accentuated by using a coloring matter in the glue.This difference in the light reflecting qualities of the face membersand cross banding is sufficient to operate the light responsive cell 93and said cell 93 will close a circuit through conductors 95 and sourceof energy 94 to the relay 92 when the cell 93 is subjected to thereflection of light from the cross banding and will open said circuit atall other times. The operation of relay 92 closes the circuit to thesolenoid 88 each time a space between the plywood face members passesthe cell 93. The operation. of solenoid'88 starts the operation of asingle revolution clutch 62 and at the same time disconnects a clutch 96through which power to drive the conveyors is transmitted to the shaftIS. The retarded relay does not necessarily close the switch St theinstant the cell 93 operates, but said relay will be timed to close theswitch 9i and stop the conveyors and start the operation of the cut offand stapling means at the time the plywood is properly positioned, forcutting and fastening. Also this retarded relay will hold the switch 9|closed until after the cut ofi and sta-.

pling devices have operated, after which it will allow the switch 9! toopen and the spring 15 will return the several parts to the positionshown in Fig. 10, thus engaging the clutch 98 and starting theconveyors. The clutch 96 is connected with the plunger 88' of solenoid88 by a link 98 ation.

Furthermore, in said Figs. 9 and 10, I have illustrated a control meansactuated by the cross banding stock betwen two adjacent panels asdistinguished from the manually controlled means of Figs. 1 to '7. Alsoin Fig. 13, a further type of control means is illustrated. Obviouslyany of the types of control means herein disclosed may be employed withthe stapling and cut, off devices of Figs. 1 to 7 or any such devices ofthe alternative constructions.

In Figs. 11 and 12 I have shown amcdified form of cut 011 means forcutting off material such as plywood stock while the material is inmotion. This means comprises a die roll i ill positioned between twoconveyors 20 and 15 with the peripheral portion of the die rollsubstantially tangent to the plane of the conveyors. A rotary knife "I2is mounted in suitable rotary knife holder means m3 above the plane ofthe conveyors and directly above the die roll Ml. Preferably the dieroll is driven at a peripheral speed equal to the speed of travel of theconveyors 2D and IT by driving means such as a friction belt I04positioned in.

contact with the die roll and supported on sheaves H35, H16, I01 andI08. Sheave I06 is driven by gear wheels I09 from shaft ill]. Shaft H0is driven from shaft I9 by belt means HI operating on sheaves H2 and H3.The several sheaves and gear wheels have the proper gear ratio to drivethe belt HM at the same speed as. the conveyors 20 and i6 and thisimparts to roll llll a peripheral speed equal to the lineal speed of theconveyors. Preferably sheave I01 is adjustable so as to serve as atightener for belt 804. The rotary knife holder it is driven through asingle revolution clutch 52 which will rotate said knife holder atpredetermined intervals through cutting cycles of one completerevolution each. Normally the knife use will be positioned clear of theroll Illi as shown by full lines in Fig. 11. When rotated it will bemoved in the same direction as the material to be cut and in the courseof its movement will make cutting engagement with the moving roll idi asshown by dotted lines in Fig. 11 and will sever while in motion anytraveling material such as plywood stock that is positioned between theknife and the roll.

Fig. 13 shows an alternative control means for automatically controllingthe operation of the stapler and cut off means by mechanical devicespositioned to contact the moving plywood, said mechanical devices beingactuated by the surface contour of the laid up plywood at the locationswhere the face members of the panels are spaced apart, and the crossbanding stock extends across- The spring H6 yieldingly urges the movableend portion of the frame member H4 upwardly but permits said movable endportion of said frame member to be moved downwardlyby pressure exertedagainst the-frame member. The bolt III limits the upward movement of themovable end portion of the frame member Ill.

The frame member H4 is positioned a short I distance below the plane oftravel of the plywood and substantially parallel to this plane andpreferably a short distance in advance of the die block 49. Airagment ofthis die block is shown in Fig. 13.

.A hook member H is mounted in the frame member Ill for longitudinalmovement relative to said frame member. This hook member IIO has a catchportion I20 positioned to engage with a shoulder I2I formed by the endportion of a lower face member 21 of the plywood. Also this hook memberI I0 is guided for longitudinal movement by means such as a slot .I22 inthe hook member through which extends a transverse pin I23 which isrigid with the frame member I I4. A tension spring I20 connects the hookmember I I9 with the frame member I and urges the hook member toward thepivoted end of the frame member II. 9

Roller means I25 is rotatably mounted on the movable end portion of theframe member II 4 beyond the catch portion I20 of the .'.ook I I9 and atthe side of the hook H9. Only one roller is shown but obviously morethan one roller may beprovided. v

Electric switch means is connected with the hook member II8 in. such amanner as to be actuated by longitudinal movement of the hook memberI-I9 relative to the housing II4. This electric switch means mayconsistof a spring switch terminal I26 mounted on the housing I I4 andadapted to be electrically contacted by an- I other spring switchterminal I21 which is carried by the hook member H9. The terminals I26and I2! are connected with electrical conductors,

such as the electrical conductors 05 of Fig. 10, so

that the operation of stapling and cut off means is controlled by theopening and closing of the circuit controlled by these terminals.

In the operation of the devices shown in Fig. 13, the laid up plywoodwill travel in the direction indicated by the arrows. The roller I25will roll on the lower surface of the plywood and the tip of the catchportion I20 of the hook I I9 will be approximately flush with theportion of the roller that engages the plywood but to the left, asrespects the showing in Fig. 13, of the point of engagement of theroller with the plywood. I When a space between the edges of adjacentface members 21 moves into registration with the catch portion I 20 ofthe hook and the roller I25, the catch portion I20 of the hook and theroller I25 will drop into this space and will engage with the crossbanding stock 20 that extends across such space as shown in Fig; 13'. Asthe plywood continues to move to the right from the position shown inFig. 13, the edge portion I2I of a lower face member 27 will engage withthe catch portion I20 of the hook member H9 and move such hook memberIIS toward the roller I25. Movement of hook member II9 toward roller I25will close the switch formed by terminals I28 and I21.

Also movement of the plywood tothe right from the position shown in Fig.13 will cause the shoul- 'der I2I formed by the edge portion of a lowerface of the catch member will-occur after the switch cut that eachclosing of the switch formed by terminals I26-I2'| will impart a cycleof operation to the stapler and cut of! means. Also it will be apparentthat the retarded relay may be timed so as to cause successive cycles ofoperation to be carried out at the proper time for stapling and cuttingoil the laid up plywood stock.

Summarizing the mode of operation of my invention, the lower facemembers 2'I are placed in line and spaced apart edge to edge relation onthe conveyor belt 20. Next, cross banding stock 26 is provided withadhesive material for both faces. I have illustrated glue rolls forapplying liquid glue to both faces of the cross banding stock. However,it is to be understood that any other well known manner of placing glueon both faces of the cross banding stock may be employed. For example,if dry powdered glue is to be used, the same may be spread on the uppersurface of the lower face members 21 and then on the upper surface ofthe cross banding stock 26. Also, film glue may be used and a film ofglue placed on the upper surface of each lower facemember 2'I and otherfilms of glue placed on the upper surface of the cross banding stock 26.The cross banding stock may be fed as a continuous strip directly ontothe lower face members 21 or the same may be fed at random width piecesof cross banding stock and positioned in edge to edge adjoining relationon the lower face members 21. In the event that wetglue is to be used, Iprefer to feed the cross bandingstock in a direction transverse of thegrain thereof and by means of the flexible conveyors 32 shown in Fig. 1.In this way the glue coated cross banding stock, whether in random widthpieces or as a continuous sheet, may be transported without wiping ofthe glue from the surfaces of the cross banding material. The crossbanding stock is placed on the lower face members and with the crossbanding stock extending continuously over both the lower face membersand the spaces between the lower face members. Then upper face membersare placed securing the face members and the 'cross bandting knife inFigs. 11 and 12, as well as the re- 7 will accomplish such purpose.

ciprocable cutting knife in Figs. 1 to 8, which However. whereefllciency may be somewhat sacritled, the cutting device illustrated inFigs. 9 and 10 may be employed. In such structure the panels are.stopped during the stapling and severing operation. Also I haveillustrated manual and automatic means for controlling the operation ofthe stapling and severing means.

After the three ply panels have been formed in the manner just setforth, they may be de- Jivered directly to a transfer means for eithercold processing or hot processing. Should multiple ply panels, otherthan three ply panels, be desired, the panels may be returned one ormore times to the head of the assembly line to form panels, as live ply,seven ply, etc. Preferably the return mechanism for returning the panelsto the head of the assembly line is in the form herein disclosed. Thisfor the reason that such permits most emcient use of men, material anddevices. Also where the conveyor system is synchronized with hot pressdevices, I may produce one five ply panel during the same interval oftime as required to produce two three ply panels, thus keeping theproduction of the conveyor line positively synchronized with the needsof the hot plate press or presses.

I claim:

1. The method of forming plywood comprising positioning a plurality offace members in line and in spaced apart edge to edge relation;providing adhesive material for both faces of the cross banding stock;placing said cross banding stock on said face members and with the crossbanding stock in edge abutting relation and ex- ..tending continuouslyover both the...fac'e members and the spaces between the face members;

placing other face members on said cross bandwith the cross bandingstock in edge abutting relation and extending continuously over both theface members and the spaces between the face members;- at a secondlocation in the line of travel of said face members placing other facemembers on said cross banding stock in substantial registrationrespectively with said first named face members; and at a third locationin the line of travel, mechanically securing together each tworegistering face members and the cross banding stock therebetween at theadjacent edges of the face members, and then cutting the portions of thecross banding stock that extend across the space between each two spacedapart face members, whereby plywood may be laid up in a travelingproduction method and the laid up units are secured together forhandling prior to the setting of the glue.

THOMAS R. ROBINSON.

